Use `defer` to do some post-modification of parent return

The case as following, but get 11 instead of 1100. Is this possible?

```r
inner <- function(x, env = parent.frame(1)) {
  withr::defer(assign("x", get("x", envir = env) * 100, envir = env), env)
}
outer <- function(x) {
  inner(x)
  x <- x + 1
  return(x)
}
outer(10)
```
